TreeMap1.java

import java.util.TreeMap;
public class TreeMap1 {
    public static void main(String[] args) {
        TreeMap<Integer, String> tree_map = new TreeMap<>();
        tree_map.put(1, "one");
        tree_map.put(2, "two");
        tree_map.put(3, "three");
        tree_map.put(4, "four");
        System.out.println("TreeMap: " + tree_map);
    }

    
}